x86/boot: Improve code generation from bootsym()
diff mbox series

Message ID 20190909104351.13444-1-andrew.cooper3@citrix.com
State New
Headers show
Series
  • x86/boot: Improve code generation from bootsym()
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Commit Message

Andrew Cooper Sept. 9, 2019, 10:43 a.m. UTC
The code generation for bootsym() is atrocious, and unnecesserily
complicated.  Given the appropriate physical address, all we need is to
construct a virtual address of the appropriate type.

  add/remove: 0/0 grow/shrink: 0/9 up/down: 0/-4256 (-4256)
  Function                                     old     new   delta
  kexec_reserve_area.constprop                 165     159      -6
  reset_videomode_after_s3                     231      70    -161
  identify_cpu                                1341    1176    -165
  parse_acpi_sleep                             408     240    -168
  early_init_intel                             632     440    -192
  __cpu_up                                    1983    1682    -301
  do_platform_op                              6469    5526    -943
  compat_platform_op                          6433    5482    -951
  __start_xen                                12939   11570   -1369
  Total: Before=3341298, After=3337042, chg -0.13%

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wl@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
---
 xen/include/asm-x86/config.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Jan Beulich Sept. 9, 2019, 10:52 a.m. UTC | #1
On 09.09.2019 12:43, Andrew Cooper wrote:
> The code generation for bootsym() is atrocious, and unnecesserily
> complicated.  Given the appropriate physical address, all we need is to
> construct a virtual address of the appropriate type.
> 
>   add/remove: 0/0 grow/shrink: 0/9 up/down: 0/-4256 (-4256)
>   Function                                     old     new   delta
>   kexec_reserve_area.constprop                 165     159      -6
>   reset_videomode_after_s3                     231      70    -161
>   identify_cpu                                1341    1176    -165
>   parse_acpi_sleep                             408     240    -168
>   early_init_intel                             632     440    -192
>   __cpu_up                                    1983    1682    -301
>   do_platform_op                              6469    5526    -943
>   compat_platform_op                          6433    5482    -951
>   __start_xen                                12939   11570   -1369
>   Total: Before=3341298, After=3337042, chg -0.13%
> 
> No functional change.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Acked-by: Jan Beulich <jbeulich@suse.com>

Patch
diff mbox series

diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
index f950247029..dab7d7bade 100644
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -91,8 +91,8 @@  extern unsigned long trampoline_phys;
 #define bootsym_phys(sym)                                 \
     (((unsigned long)&(sym)-(unsigned long)&trampoline_start)+trampoline_phys)
 #define bootsym(sym)                                      \
-    (*RELOC_HIDE((typeof(&(sym)))__va(__pa(&(sym))),      \
-                 trampoline_phys-__pa(trampoline_start)))
+    (*((typeof(sym) *)__va(bootsym_phys(sym))))
+
 extern char trampoline_start[], trampoline_end[];
 extern char trampoline_realmode_entry[];
 extern unsigned int trampoline_xen_phys_start;